Two days ago, gunmen attacked a house in the small town of Khalis and killed the brother of the deputy mayor, another in a string of insurgent attacks focused on local officials. On Tuesday, as the dead man's family and town dignitaries gathered to pay their respects in a tent set up for the funeral, a suicide bomber drove a car toward the tent and set off a powerful bomb.

The blast in Khalis, 40 miles north of Baghdad, killed 14 people and wounded 70, according to local officials.

"The hospitals are full of victims," Maj. Gen. Waleed Khalid Abdul Salam, the police chief in the nearby city of Baqubah, said on al-Jazeera television. "I think the explosion was aimed at the mayor."

There was no assertion of responsibility for the bombing, which occurred shortly after the governor of Diyala province and all the members of a local governing council had left the gathering.

The continuing attacks on Iraqis provoked a tough new response Tuesday from the country's interim prime minister, Ayad Allawi. Vowing that "there will be no more safe havens for terrorists," Allawi said in a statement that the Iraqi government had pinpointed a house in Fallujah connected to the network of the Jordanian guerrilla Abu Musab Zarqawi and directed U.S. military jets to attack it on Monday. The airstrike, which employed two tons of precision bombs, reportedly killed 15 people, including women and children.

Allawi was unapologetic about civilian casualties: "This operation was launched to terminate these terrorists, whose vehicle bombs and suicide vests indiscriminately kill innocent Iraqis, and destroy Iraqi schools, hospitals and police stations. The people of Iraq will not tolerate terrorist groups or those who collaborate with any other foreign fighters such as the Zarqawi network to continue their wicked ways."

While Allawi laid down the interim government's hard line, four masked men holding automatic weapons and rocket-propelled grenade launchers appeared on al-Arabiya television threatening to kill Zarqawi, who is believed to be responsible for a string of car bombings, kidnappings, beheadings and other attacks.

Calling themselves the Relief Movement, the men issued a challenge to Zarqawi, who U.S. officials say is linked to al Qaeda and who apparently began working in Iraq in the chaotic aftermath of last year's U.S.-led invasion.

"We tell Zarqawi, the criminal, that he has to go out of Iraq immediately, he and his followers," the group said. They railed that "innocent people were killed" by Zarqawi's action.

"What is his religion? Is it Islam, religion of peace, that allows him to do the explosions on a holy day in a holy city, or to car-bomb police stations or a commercial street to kill thousands of innocents? What religion is it that allows him and his followers to kidnap and slaughter foreign workers without any guilt? Who is he to threaten Ayad Allawi and kill our religious and patriotic personnel?"

U.S. officials have called Zarqawi the most wanted man in Iraq and have offered a $25 million reward for him.

In other violence on Tuesday, three U.S. Marines died in Anbar province in western Iraq. The U.S. military declined to provide details of the incident.

[On Wednesday, the U.S. military announced that another four Marines were killed Tuesday by guerrillas west of Baghdad, the Reuters news agency reported.]

U.S. military officials acknowledged that a child was killed and another child wounded Monday night when soldiers opened fire on a car that had failed to stop at a checkpoint in Baghdad. An Army spokesman said the driver of the car switched off his vehicle lights and kept moving after being ordered to stop.

Despite the deployment of Iraqi police in the city, traffic in Baghdad is chaotic and unruly. U.S. soldiers and Iraqi National Guardsmen and police are often tense at checkpoints, which have been the targets of frequent attacks. American soldiers often issue orders in English that Iraqi drivers do not understand.

In the southern city of Basra, one civilian was killed and two were injured by a roadside bomb apparently intended for a British military convoy, according to Iraqi police.